Transmission schemes of radio channels of mobile communication networks typically employ a sequence of subframes for transmission, i.e. sending and/or receiving, of data. The data may for example include payload data and control data. Further, also reference signals may be transmitted. That is to say, different types and signals of data may be transmitted.
The subframes may have a well-defined temporal duration, e.g., typically in the millisecond regime, and may comprise a plurality of symbols carrying the data or the reference signals. The symbols may be defined with respect to a time-frequency resource scheme comprising resource elements. The resource elements may be a smallest time-frequency unit used for the transmission on the radio channel. A symbol may include a plurality of resource elements having different frequencies. For example, each resource element of a symbol may occupy a different frequency band (sub-carrier). A certain number of resource elements/symbols may constitute the subframe. Signals received for each resource element by a receiver over the course of time may correspond to the symbols. The symbols may be encoded using a certain encoding scheme, e.g., Orthogonal Frequency-Division Multiplex (OFDM).
The various parameters of the time-frequency resource scheme, e.g., number of resource elements per subframe, number of sub-carriers, temporal duration of a resource element, frequency bandwidth of a subcarrier, and/or allocation of resource elements for various data types, etc., are typically defined within the framework of a certain mobile communication network standard. Furthermore, they may be dependent on a number of parameters, including, but not limited to: uplink data transmission and downlink data transmission.
In general, the various resource elements of a subframe may have different transmission properties such as transmission power used for sending of the respective signals. For example, it is possible that resource elements relating to signals used for transmission of control data (control data resource elements) are sent by a sender using a larger transmission power than resource elements relating to signals used for transmission of payload data (payload data resource elements). Also, it is possible that resource elements relating to signals used for transmission of reference signals (reference signal resource elements) are sent using a larger transmission power than payload data resource elements.
The transmission schemes may support uplink data transmission, i.e., transmission from a user equipment (UE) of a subscriber connected to the mobile communication network; and downlink data transmission, i.e., transmission from the mobile communication network to the UE. Typically, downlink and uplink transmission capacity is allocated using certain schemes which depend on various parameters including certain time and/or frequency allocation schemes for multiplexing between different UEs.
An example of a mobile communications network relying on a radio channel employing subframes is the Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) standard, where details of the subframe are defined in the Technical Specification (TS) 36.211 Version 11.1.0 of December 2012, chapter 4 “Frame structure”.
Scenarios are known where a certain degree of flexibility in the transmission properties, in particular the allocation of uplink and downlink transmission capacity for the radio channel, is provided. The transmission properties may relate to one or more of the following: scheduling and timing of the subframes, allocation of resource elements of a subframe for transmission of different types of data such as payload data and/or control data and/or reference signals, transmission power.
For example, it may be possible to dynamically allocate transmission capacity for either downlink transmission or uplink transmission for a radio channel. This may promote fast data transmission and result in tailored network properties depending on the current transmission demand of a particular subscriber. In particular if compared to a static or semi-static allocation of transmission capacity, a more flexible scenario better matching a current data traffic situation may be feasible. System performance may be optimized. Such scenarios are known, e.g., as dynamic Time Division Duplexing (TDD) in the 3GPP environment. See for example 3GPP R1-120781, “Isolated cell performance for LTE TDD traffic adaptation”, Ericsson (February 2012).
Yet such scenarios may face certain restrictions. For example, if transmission capacity is individually allocated for various radio channels, i.e., allocation may occur for a given radio channel independently or largely independently of other radio channels, increased interference between the given radio channel and the other radio channels may result, in particular with respect to neighboring radio channels in spatial vicinity.
Therefore, a need exists for techniques which allow for providing transmission on a radio channel with reduced impairment from interference from other radio channels.